We can't make anyone come to an aikido class, PTSD or not, VA or not. And it is dangerous to think that someone else needs what we have to offer. Offer it in general, let the folks who can use it pick it up.
I think you are entirely right to show up, be available, and give what you have to those who show up. Anything more is coercion, or flat out ignoring what the vets say they need.